diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index ca48abda5fc16..0e2da2b02ca0f 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -1417,9 +1417,7 @@ impl<'test> TestCx<'test> {
     }
 
     fn is_rustdoc(&self) -> bool {
-        self.config.src_base.ends_with("rustdoc-ui")
-            || self.config.src_base.ends_with("rustdoc-js")
-            || self.config.src_base.ends_with("rustdoc-json")
+        matches!(self.config.suite.as_str(), "rustdoc-ui" | "rustdoc-js" | "rustdoc-json")
     }
 
     fn get_mir_dump_dir(&self) -> PathBuf {
diff --git a/src/tools/compiletest/src/runtest/rustdoc_json.rs b/src/tools/compiletest/src/runtest/rustdoc_json.rs
index 31fdb0a5d13bd..bf7eb2e109a46 100644
--- a/src/tools/compiletest/src/runtest/rustdoc_json.rs
+++ b/src/tools/compiletest/src/runtest/rustdoc_json.rs
@@ -16,13 +16,12 @@ impl TestCx<'_> {
             self.fatal_proc_rec("rustdoc failed!", &proc_res);
         }
 
-        let root = self.config.find_rust_src_root().unwrap();
         let mut json_out = out_dir.join(self.testpaths.file.file_stem().unwrap());
         json_out.set_extension("json");
         let res = self.run_command_to_procres(
             Command::new(self.config.jsondocck_path.as_ref().unwrap())
                 .arg("--doc-dir")
-                .arg(root.join(&out_dir))
+                .arg(&out_dir)
                 .arg("--template")
                 .arg(&self.testpaths.file),
         );